<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>div1</div>
<div>div2</div>
<div>div3</div>
<input type="button" value="按钮" onclick="fn()">
<script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>
<script>
    //创建
    let d=$("<div>我是新来的</div>");
    $("body").append(d);
    //删除
    $("div:first").remove();
    function fn() {
        //隐藏
        $("div").hide();
    }
</script>
</body>
</html>